手机壁纸设置相关

framework 服务

frameworks\base\core\java\android\app\IWallpaperManager.aidl

与设置获取墙纸相关的服务端接口

frameworks\base\core\java\android\app\IWallpaperManagerCallback.aidl

oneway interface IWallpaperManagerCallback {    /**     * Called when the wallpaper has changed     */    void onWallpaperChanged();}

当服务端墙纸内容准备好，准备显示时，会回调onWallpaperChanged通知客户端。

frameworks\base\core\java\android\app\WallpaperManager.java

墙纸服务管理类，其内部类

static class Globals extends IWallpaperManagerCallback.Stub {    private IWallpaperManager mService;    private Bitmap mCachedWallpaper;    private int mCachedWallpaperUserId;    private Bitmap mDefaultWallpaper;    Globals(Looper looper) {        IBinder b = ServiceManager.getService(Context.WALLPAPER_SERVICE);        mService = IWallpaperManager.Stub.asInterface(b);        forgetLoadedWallpaper();    }

// Private completion callback for setWallpaper() synchronizationprivate class WallpaperSetCompletion extends IWallpaperManagerCallback.Stub {    final CountDownLatch mLatch;    public WallpaperSetCompletion() {        mLatch = new CountDownLatch(1);    }

内部类Globals 获取墙纸服务，并实现客户端回调接口

内部类WallpaperSetCompletion 用于服务内部使用，设置墙纸完成回调。

frameworks\base\services\core\java\com\android\server\wallpaper\WallpaperManagerService.java

public class WallpaperManagerService extends IWallpaperManager.Stub {    static final String TAG = "WallpaperManagerService";    static final boolean DEBUG = false;    public static class Lifecycle extends SystemService {        private WallpaperManagerService mService;        public Lifecycle(Context context) {            super(context);        }        @Override        public void onStart() {            mService = new WallpaperManagerService(getContext());            publishBinderService(Context.WALLPAPER_SERVICE, mService);        }

实现墙纸服务客户端，并发布服务。

应用端

frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\LockscreenWallpaper.java

public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implements Runnable {    private static final String TAG = "LockscreenWallpaper";    private final PhoneStatusBar mBar;    private final WallpaperManager mWallpaperManager;    private final Handler mH;    private boolean mCached;    private Bitmap mCache;    private int mCurrentUserId;    // The user selected in the UI, or null if no user is selected or UI doesn't support selecting    // users.    private UserHandle mSelectedUser;    private AsyncTask<Void, Void, LoaderResult> mLoader;    public LockscreenWallpaper(Context ctx, PhoneStatusBar bar, Handler h) {        mBar = bar;        mH = h;        mWallpaperManager = (WallpaperManager) ctx.getSystemService(Context.WALLPAPER_SERVICE);        mCurrentUserId = ActivityManager.getCurrentUser();        IWallpaperManager service = IWallpaperManager.Stub.asInterface(                ServiceManager.getService(Context.WALLPAPER_SERVICE));        try {            service.setLockWallpaperCallback(this);        } catch (RemoteException e) {            Log.e(TAG, "System dead?" + e);        }    }

锁屏墙纸实现了 onWallpaperChanged接口并继承runnable ，这样当壁纸准备好可以显示时就会调用该接口，而该接口将该类post 到主线程，从而执行该类中run 函数。当加载完壁纸，这更新状态栏，mBar.updateMediaMetaData。

frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\PhoneStatusBar.java

if (ENABLE_LOCKSCREEN_WALLPAPER) {    mLockscreenWallpaper = new LockscreenWallpaper(mContext, this, mHandler);}

桌面背景壁纸服务类

frameworks\base\core\java\android\service\wallpaper\WallpaperService.java